Dynamic assessment of cerebral blood flow and intracranial pressure during inversion table tilt using ultrasonography

J Neurol Sci. 2019 Sep 15:404:150-156. doi: 10.1016/j.jns.2019.07.033. Epub 2019 Jul 31.


Context: Inversion tables are used as treatment for back pain, but there is a lack of agreement on systemic effects of inversion.

Objective: To assess intracranial pressure (ICP) and cerebral blood flow using ultrasonography during inversion table tilt.

Methods: Optic nerve sheath diameter (ONSD), heart rate (HR), blood pressure, internal carotid artery (ICA) and middle cerebral artery (MCA) blood flow of participants were measured in 3 positions: supine before inversion, during inversion with head down, and supine post-inversion. ONSD was evaluated with ocular ultrasonography and blood flow (ICA and MCA) with Doppler ultrasonography.

Results: The ONSD changed significantly between the supine position, at 3 min of inversion, and after returning to supine position (all P < .001). The post-inversion HR was less than pre-inversion (P = .03) and 3-min inversion HR (P = .003). There were significant changes in ICA and MCA flow caused by inversion, which affected blood flow velocity, resistance, and pulsatility index (all P ≤ .005).

Conclusion: Inversion caused significant changes in ICP and blood flow. Thus, increased chance of complications may exist when using inversion as a therapeutic tool or during surgical procedures in patients with previous history of elevated ICP. These results demonstrate that inversion therapy should be used with caution.

Keywords: Carotid Doppler; Intracranial pressure; Inversion table; Optic nerve sheath diameter; Transcranial Doppler; Ultrasonography.

MeSH terms

  • Adult
  • Blood Flow Velocity / physiology
  • Cerebrovascular Circulation / physiology*
  • Female
  • Hemodynamics / physiology
  • Humans
  • Intracranial Pressure / physiology*
  • Male
  • Optic Nerve / diagnostic imaging*
  • Patient Positioning*
  • Ultrasonography
  • Young Adult